From Urtica dioica

Balzarini J, Neyts J, Schols D, Hosoya M, Van Damme E, Peumans W, De Clercq E. The mannose-specific plant lectins from Cymbidium hybrid and Epipactis helleborine and the (TV-acetylglucosamine)w-specific plant lectin from Urtica dioica are potent and selective inhibitors of human immunodeficiency virus and cytomegalovirus replication in vitro. Antiviral Res 1992 18 191-207. 

Lectins The mannose-specific plant lectins from Galanthus, Hippeastrum, Narcissus, Epipactis helleborine, and Listera ovata, and the V-acctylglucosaminc-spccilic lectin from Urtica dioica would primarily be targeted at the virus-cell fusion process. 

A number of mannose-specific agglutinines (lectins) from Galanthus nivalis, Hippeastrum hybrid, Narcissus pseudonarcissus, Listera ovata, Cymbidium hybrid, Epipactis helleborine, and the N-acetylglucosamine-specific lectin from Urtica dioica have been found to inhibit HIV-1 and HIV-2 infection at similar concentrations as dextran sulfate (IC50 0.2 to 0.6 fig/ml), or even lower (IC50 0.04 to 0.08 pg/ml. Akin to sulfated polysaccharides, the plant lectins also exhibit activity against various enveloped viruses other than HIV, i.e., HSV-1, HSV-2, CMV, RSV, and influenza virus. Plant lectins would primarily interfere with the virus-cell fusion process. Their precise mode of action remains to be resolved. 

Antonopoulou, S., C.A. Demopoulos, and N.K. Andrikopoulos. 1996. Lipid separation from Urtica dioica Existence of plateletactivating factor. /. Agric. Food Chem. 44 3052-3056. 

Kraus S, Wagner H (1998) UPS I, a chemotactic polysaccharide isolated from Urtica dioica. Phytomedicine in press... 

Chlorogenic acid is one of the active components in a herb Urtica dioica L. (Urticaceae) and has been utilized for the treatment of rheumatoid arthritis. Chlorogenic acid from the plant demonstrates moderate inhibitions against the 5-LOX pathway with IC50 = 83 pM and COX pathway with IC50 = 38 pM [163]. However, caffeic acid has been reported as a weak inhibitors against 5-LOX (IC50 = 200 pM) and showed no inhibition on COX pathway [164]. 

M Schottner, D GanBer, G Spiteller. Lignans from the root of Urtica dioica and their metabolites bind to human sex hormone binding globulin (SHBG). Planta Medica 63 529-632, 1997. 

Edwards, S.C., MacLeod, C.L., Lester, J.N., 1998. The bioavailability of copper and mercury to the common nettle Urtica dioica) and the earthworm Eisenia ferida from contaminated dredge spoil. Water Air Soil Pollut. 102, 75-90. 

Other Western herbs that have been investigated for the treatment of BPH include pumpkin seeds (Cucurbita pepo), nettle root (Urtica dioica or Urtica urens), bee pollen (particularly that from the rye plant), African potato (tubers of Hypoxis rooperi), and the African tree Pygeum africanum, also known as Prunus africanum. In most cases, but particularly with pumpkin seeds and African potato, the main active components are sterols, such as p-sitosterol, which also has been used for BPH. 

Of special interest is the fact that certain plants synthesize secondary products which in animals possess hormone or antihormone activity. Either the true animal hormones are formed (Table 59) or substances are built which mimic the animal hormones (Table 76). Both types of compounds may cause metabolic and developmental abnormalities in the predators, reduce reproduction, or, in the case of the trichomes of the stinging nettel (Urtica dioica) containing histamine (D 20) and serotonin (D 21.1), cause irritation of in the skin after injection which may repel predators. Rather large quantities of the hormones may be produced, as is shown by the fact that from 1 g of dried rhizomes of the fern Polypodiurn vulgare, 10 mg ecdysterone were isolated, in striking contrast to the 0.33 mg isolated from a ton of silkworms. 

Some other anti-complementary acidic pectic arabinogalactans including rhamnogalacturonan core and arabinan have also been isolated from medicinal herbs such as the roots of Angelica acutiloba (AGIIb-1) [24-27], berries of Viscum album (Fig. 2) [29], and the roots of Urtica dioica [51]. Their arabinogalactan parts were also characterized as arabino-p-3,6-galactan. 

American material is designated U. dioica subsp. gracilis (Ait.) Seland., consisting of six varieties. The American material differs from the typical European Urtica dioica subsp. dioica primarily in that it has male and female flowers on the same plant. Some botanists treat the varieties of U. dioica subsp. gracilis as separate species. 

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